Quick links to various main topics in my blog

Along the axis of the Avenue, there's a 134m high bump in the landscape just north west of Durrington Walls which blocks the view of the point I chose on Sidbury Hill's southern flank.

Here's that plot:

However, that 134m bump is only a few tens of metres wide, and by shifting gaze about 0.5° to the north of the Avenue axis, two things happen.

1) You're now looking at the highest point of Sidbury Hill, instead of towards the southern flank

2) You're looking over a 125m ridge, not at a 134m bump.

Here's that plot:

I now suspect that (if the modern trees weren't in the way) you'd see a notch in the landscape between Sidbury Hill on the left in the far distance (8 miles) and the 134m bump NW of Durrington Walls on the right in the near distance (2.5 miles) - and the Sun would rise through that notch on the summer solstice.

--
simon

Bloody fascinating btw....

--
bombholio

Kinda like this:

--
bombholio

--
DrGoon

This morning was clear and bright, and being only 2 days after solstice the Sun's rising in pretty much exactly the same place as it did on the 21st.

So I went and stood on the axis from the Avenue towards Sidbury Hill (NB: SiDbury, not SiLbury - to avoid some evident confusion), on the side of the 134m hump mentioned earlier in this thread, on the road up to Larkhill from Durrington - here's a map:

Blue line indicates alignment along Avenue towards Sidbury Hill.

... and took some photos of sunrise, to see if it really did rise where I said it would:

Told you so :-)

To get the overall feel for the view, here's a quick panorama shot:

Well worth getting up for at 4.30am, I reckon.

--
simon

PS: Our place is slightly to the north and west of the alignment from the Avenue to Sidbury Hill, and the ground slopes up towards the north east, so we get sunrise about 20 minutes later over the end of our back garden.

When I get the webcam properly mounted on the roof sometime in the coming year, we should see the sun rise directly out of the top of Sidbury Hill (which you can just see from our upstairs window). For now, here's a pic taken from our garden this morning on returning from Larkhill:

Updated 2006-08-18: I went back to the same location in Larkhill to try and take a picture of the northernmost Moonrise.

--

It just won't take a picture without faffing about whirring and gooping even when it's allegedly set to 'infinity'.

The result is it's pretty vague about what 'infinity' is, and the depth of field even at f8 sometimes doesn't get there.

Gimme a manual focus any time.

Thankfully, digital SLRs are finally coming down enough in price to consider getting one some time.
--
simon

My Nikon D50 was under $500 - a factory refurb, but through a reputable dealer. DSLRs appear to be one of those things you should buy on a US visit.
--
DrGoon

Upgraded to Google Earth Plus, and downloaded the beta of version 4. This allows me to save paths, which is a great help.

Anyway, I was up on Sidbury Hill yesterday afternoon, OS map in hand, figuring out the path of the solstice alignment south-west back towards Stonehenge.

On the far horizon, maybe 30 miles away I could make out a distinctive oddly shaped hill. It seems that Stonehenge is on the solstice alignment line between that hill and Sidbury.

Projecting the line between Sidbury and Stonehenge back towards the south-west, the first hill encountered which is high enough to project against the skyline from Sidbury Hill (224m) appears to be Melbury Hill (236m), a couple of miles south of Shaftesbury.

Here's a screenshot (you may want to open the full size version from the Attachments link below, if you're following along in detail):

The .kml placemarks for Google Earth for Melbury and Sidbury Hills are attached below.

Also on or very close next to this alignment are some interesting other features:

Chicksgrove

Grovely Castle (white line is the path of the alignment)

Stapleford Castle

and of course:

Stonehenge

If it wasn't tipping down with rain right now, I'd be on top of Melbury Hill with a map and a camera :-) Next week maybe.

Of course this means that, come Winter Solstice, I'm going to have to be up on top of Sidbury Hill to watch the sun set into Melbury Hill, 30 miles away.
--
simon

I've got a copy of Alfred Watkins' 1925 book "The Old Straight Track" which I picked up at the Megalithomania conference but haven't read it yet (still stuck in the middle of All Done with Mirrors).

Watkins never visited the Stonehenge area, but flicking through the index of his book I see he advanced the idea that Sidbury was involved in a Stonehenge alignment, but in the appendix he reports he's been informed that Stonehenge and Sidbury aren't intervisible.

Idle musing - I wonder if you could see Sidbury if you stood on the top of the lintel ring at Stonehenge, or on the even higher great trilithon (of which only one stone still stands). It'd put you at least 30 feet higher off the ground.
--
simon

Idle musing - I wonder if you could see Sidbury if you stood on the top of the lintel ring at Stonehenge, or on the even higher great trilithon (of which only one stone still stands). It'd put you at least 30 feet higher off the ground.

(and now, some 4 years later....)

I've happened across http://www.heywhatsthat.com/ and it's a very handy thing for determining intervisibility based on terrain modelling.

I just had to have a go at putting my eyes 30' up in the air by standing on top of the Grand Trilithon at Stonehenge to see if I'd be able to see Sidbury Hill poking up above Larkhill.

I've attached some screengrabs of the output which speak nicely for themselves :-)

The red shading is the terrain that's visible if you were to stand on top of the Grand Trilithon at Stonehenge. Purple cross is Stonehenge, black one is Sidbury Hill

Horizon and ground profile looking on a bearing of 49° towards Sidbury Hill as seen from atop the Grand Trilithon. In the ground trace, the large bump on the right hand side is Sidbury Hill - notice how the sightline just manages to clear the ridge at Larkhill

Check back up this thread to find my earlier ground traces done the old fashioned way.
--
simon